The Sonix division of Walker Magnetics Groups, Inc. has developed an ultrasound device which uses the frequency dependent characteristics of bone to measure the density and structure of trabecular bone in vivo. A prototype unit is being utilized to clinically evaluate the utility of measurements of the os calcis (heel) to diagnose the progress of osteoporosis. This research will utilize the feedback from these studies to modify the hardware and technique to improve the repeatability and verify the efficiency of the apparatus, for use in clinical screening for osteoporosis. Specifically, Dr. Millner and Dr. Langton will support and coordinate on-going studies of the device's utility, using comments of technicians and physicians to determine areas needing improvement. Design modifications will be made and introduced to the users. These will include improved heel positioning controls and modification or elimination of the present water bath. A final report will describe the measurement repeatability and the correlation of results with other methods of screening for osteoporosis.